This invention relates to a duplex optical connector, which is assembled by joining a pair of simplex optical plugs in a side-by-side relationship.
In communication systems, it is frequently desirable to make connections with paired transmission media where, for example, each medium carries information in a different direction. In optical systems, precision alignment is critical and it is customary to use specially designed connectors for aligning each optical fiber. Nevertheless the desire for customer convenience has led to the development of duplex optical connectors which include two optical fibers and the means for aligning same. For example, U.S. Pat. No. 4,787,706 discloses a duplex optical fiber connector for terminating a cable containing a pair of buffered optical fibersxe2x80x94each held within a fiber-holding assembly comprising a ferrule and a spring-loaded base member. The fiber-holding assemblies are contained within a common housing that is formed to include two flexible molded plastic sidearm members for interlocking with a mating receptacle. The housing includes details that can be used for assuring polarization during interconnection with another optical fiber connector. And while this connector provides excellent performance, it requires its own family of connecting apparatus and does not interconnect with apparatus designed for unitary (simplex) connectors.
U.S. Pat. Nos. 4,953,929 and 5,123,071 disclose examples of duplex connectors that yoke a pair of simplex optical plugs together in a duplex configuration. However, such connectors rely on the simplex plugs themselves for interlocking with an associated receptacle. In this situation, the latching mechanism associated with each simplex plug needs to be properly activated to assure good optical connections. Moreover, it is cumbersome to assemble and disassemble the simplex plugs to and from the yoke structures disclosed in these duplex connectors.
U.S. Pat. Nos. 5,481,634 and 5,923,805 disclose low-profile, simplex optical plugs that are known as LC-type optical plugs. Such optical plugs are manufactured by Lucent Technologies. The LC plug is advantageous because it has a smaller footprint than any of its predecessor optical plugs; and it can be used effectively in high-density, panel-mounted applications. Additionally, its design resembles the user-friendly, RJ-style modular plugs that are used in conventional telephone sets. LC optical plugs have become so popular, in fact, that it is desirable to have an apparatus that would yoke a pair of LC plugs, or the like, into a duplex configuration. And although such an apparatus is already available (see U.S. Pat. No. 5,579,425), it also relies on the individual simplex plugs for interlocking with an associated receptacle.
Accordingly, it is desirable to provide a duplex connector that joins a pair of low-profile, simplex optical plugs together into a single structure. Moreover, it is desirable that the associated simplex plugs be quickly and easily assembled and disassembled to and from the duplex connector. Finally, it is desirable for the duplex connector to have its own latching apparatus, which is separate from the latching apparatus of the simplex connectors, for interlocking with an associated receptacle.
A duplex connector that includes a pair of side-by-side optical ports having internal walls that define a pair of cavities overcomes the above-described deficiencies. Each cavity has an opening in its back end that is shaped to receive a low-profile optical plug, and each cavity has a tubular boss at its front end that is shaped to receive a ferrule that holds an optical fiber. The bosses project outward from the front end of the duplex connector in a direction that is parallel to the longitudinal axis of the cavity. Preferably, each tubular boss contains an alignment sleeve for aligning the central axes of a pair of ferrules that are inserted into the opposite ends of the alignment sleeve. Associated with each cavity is a retaining feature that interlocks with a mating feature on the optical plug and prevents inadvertent decoupling between the plug and cavity. Similarly, the duplex connector itself includes a latching member on an outside surface for interlocking with a mating member that resides on a receptacle, which is designed to receive the duplex connector. These items allow individual simplex optical connectors to be easily assembled and disassembled to and from the duplex connector, and allow the duplex connector to be easily installed and removed from the receptacle using its own latching mechanism(s).
In an illustrative embodiment of the invention, the duplex connector includes cantilever latching members on its top and bottom sides, and the cavities are shaped to receive LC-type optical plugs. Also, in the illustrative embodiment, tongue-like projections (guide members) reside on the top and bottom sides of the connector that perform a number of valuable functions. The guide member on the bottom side is slightly wider than the guide member on the top side to provide a xe2x80x9ckeyingxe2x80x9d feature that prevents improper (upside down) insertion of the duplex connector into the receptacle. More importantly, the guide members provide additional strength to withstand side-loading forces that would otherwise be transferred to the alignment sleeves.